Driver Seat Forward Switch Circuit Short to Ground
The B1720 code indicates a short to ground in the driver seat forward switch circuit. This switch controls the forward movement of the power seat. The seat control module detects an abnormally low voltage signal on the forward switch circuit, typically caused by the wiring or the switch itself being shorted to ground. The system continuously monitors resistance and voltage in the seat motor circuits to detect electrical faults.
1. Commonly Affected Makes
2. Most Common Causes
- Faulty or moisture-damaged driver seat forward switch
- Wiring harness shorted to ground (due to chafing, rodent damage, or mechanical damage)
- Corroded or bent pins in the switch connector
- Internal seat motor fault affecting the control circuit
- Faulty seat control module (MSM) internal detection circuit
3. Symptoms You Will Notice
- Driver power seat does not move forward
- Seat may move in other directions but not forward
- Seat moves intermittently or only with manual assistance
4. Step-by-Step Diagnosis
Check for technical service bulletins (TSBs) related to B1720
Visually inspect the seat forward switch and wiring for damage, corrosion, or moisture
Test the switch continuity and resistance with a multimeter
Check for shorts to ground in the wiring between the switch and the seat control module
If wiring and switch are okay, test the seat motor and control module per manufacturer procedures
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, it is generally safe to drive. The fault only affects the forward movement of the driver seat, which may be inconvenient but does not impact vehicle safety.
How much does it cost to fix?▼
Repair costs typically range from $100 to $400, depending on whether the switch, wiring, or control module needs replacement. Diagnostic fees may add $50–$100.